Lykke Li took time out from her whirlwind tour of major American cities yesterday to make an appearance on the Tonight Show. The Swedish songwriter performed "Youth Knows No Pain," the brooding yet up-tempo opening track from her latest album Wounded Rhymes. The tune is like a Sixties, organ-heavy garage rock tune with a Euro-goth makeover, so naturally, Li and her band showed up dressed entirely in black and swayed around like a bunch of sexy True Blood vampires.